Hi Art Yep you quite right "back it up" is a first priority . I like the idea of your Scan2 cad .How do you use it ?
The programme enables you to scan any picture or plan into the computer and convert it into a Cad drawing for further modification, enlargement, scaling etc. as if you were creating an original in Autocad.
The cad result will only be as good as the original quality pic, so some 'cleaning up' of the scan is sometimes required/or abandonement as the case may be.
I find it particularly useful to scan large plans ( tiled), join them up into one plan again and then print out different scales. This is time consuming but the end result of scaling the 1:200 scale IJN Shinano plan into a 19' 1:48 scale plan was nigh on perfect. Far better, ( and cheaper! ) and more accurate than having them photocopied to a larger scale.
I am in the process of putting all my model sheets, ( 200 + ) onto disc this way and it is an on-going process as you can imagine.
Photo's are also scanned and drawings made off them. You *do* have to know the actual measurements of something in the pic, but once that has been entered, everything else scales up accordingly and you have a very accurate rendition.
Still learning and playing with the programme.
There is a free 14 day trial for download at
http://www.softcover.com
I can thoroughly recommend it for modellers wanting to get that obscure/unavailable plan and not wanting to go to the hassle of learning an autocad programme.